Creating and Updating my Experiments

create-empirica-app requires Node.js >= 8. If you don't already have Node.js 8+ setup, we recommend you use the official installer:

You will also need Meteor, for which you can follow the instructions at

Then you can simply run the following command, where my-experiment is the name of the experiment you wish to create:

npx create-empirica-app my-experiment

It will create a directory called my-experiment inside the current folder. Inside that directory, it will generate the initial project structure and install the transitive dependencies:

├── .meteor
├── node_modules
├── package.json
├── package-lock.json
├── .gitignore
├── public
├── client
│ ├── main.html
│ ├── main.js
│ ├── main.css
│ ├── game
│ │ └── ...
│ ├── intro
│ │ └── ...
│ └── exit
│ └── ...
└── server
├── main.js
├── callbacks.js
└── bots.js

No configuration or complicated folder structures, just the files you need to build your app. Once the installation is done, you can open your project folder:

cd my-experiment

Inside the newly created project, you can run the standard meteor command to start you app locally:


meteor runs the app in development mode. Open http://localhost:3000 to view it in the browser.

The page will automatically reload if you make changes to the code. You will see the build errors in the console.

Finding out which version of Empirica Core I have

If you are unsure as to which version of Empirica you have, you can run this line in your app to show you all the elements in the app, including Empirica Core:

meteor list

Updating Empirica Core

As new versions of Empirica become available, you might want to update the version you are using in your app. To do so, simply run:

meteor update empirica:core